A new method for predicting chlorophyll-a concentration in a reservoir: Coupling EFDC hydrodynamic and water quality model with ConvLSTM-MLP network

Journal of Hydrology, Journal Year: 2025, Volume and Issue: unknown, P. 133485 - 133485

Published: May 1, 2025

Language: Английский

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A novel algorithm for estimating phytoplankton algal density in inland eutrophic lakes based on Sentinel-3 OLCI images

International Journal of Applied Earth Observation and Geoinformation, Journal Year: 2024, Volume and Issue: 129, P. 103800 - 103800

Published: April 1, 2024

As one of the optically active components, phytoplankton are common photosynthetic organisms in oceans, nearshore, and inland water bodies. The variations algal density play a crucial role understanding primary productivity, carbon cycling, early warning blooms. In this study, three typical eutrophic lakes China, Lake Taihu, Chaohu, Dianchi, were taken as research area. Algorithms for estimating cyanobacteria-dominated non-cyanobacteria-dominated types developed based on Mie theory. results demonstrated that algorithm had favorable estimation performance lakes, with determination coefficient (R2) 0.88, mean absolute percentage error (MAPE) 51%, an unbiased (UMAPE) 39%, root square (RMSE) 23.99 × 106 cells/L. Furthermore, comparison other algorithms showed lowest MAPE 60% UMAPE 43%, RMSE 23.42 106cells/L. Extensive evaluation satellite-ground synchronous data applicability to Sentinel-3 OLCI sensor, enabling spatial temporal distribution characteristics from 2016 2022 using images. inversion revealed continuous decreasing trend Dianchi 2022, while Taihu Chaohu both decreased after 2019.

Language: Английский

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Assessment of estrogenic potential from exudates of microcystin-producing and non-microcystin-producing Microcystis by metabolomics, machine learning and E-screen assay

Journal of Hazardous Materials, Journal Year: 2024, Volume and Issue: 470, P. 134170 - 134170

Published: April 9, 2024

Cyanobacterial blooms, often dominated by Microcystis aeruginosa, are capable of producing estrogenic effects. It is important to identify specific compounds produced cyanobacteria, though this can prove challenging owing the complexity exudate mixtures. In study, we used untargeted metabolomics compare components exudates from microcystin-producing and non-microcystin-producing M. aeruginosa strains that differed with respect their ability produce microcystins, across two growth phases. We identified 416 chemicals found similar components, mainly organoheterocyclic (20.2%), organic acids derivatives (17.3%), phenylpropanoids polyketides (12.7%), benzenoids (12.0%), lipids lipid-like molecules (11.5%), oxygen (10.1%). then predicted group using random forest machine learning. Six (daidzin, biochanin A, phenylethylamine, rhein, o-Cresol, arbutin) belonging (3), (2), compound (1) were tested exhibited potency based upon E-screen assay. This study confirmed both contain properties, a growing concern in cyanobacteria management.

Language: Английский

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Comparative Study on the Determination of Chlorophyll-a in Lake Phytoplankton by a YSI Multi-Parameter Water Quality Meter and Laboratory Spectrophotometric Method

Water, Journal Year: 2024, Volume and Issue: 16(10), P. 1350 - 1350

Published: May 9, 2024

Algal blooms caused by eutrophication are a major global problem, and the monitoring prediction of algal densities in lakes important indicators management. However, reliability commonly used chlorophyll-a (Chl-a) to characterize phytoplankton density lake environments needs be further investigated. In this paper, we sampled analyzed 365 samples from nine plateau Yunnan Province during dry rainy seasons. The Chl-a data measured laboratory spectrophotometric method portable YSI multi-parameter water quality meter (YSI) directly field were compared, regression analysis correlation with performed. Most values instrument greater than those YSI, between two methods was weak (0.492, p < 0.001). reached 0.67 (p 0.001) season, while measure may have led an overestimation due nonspecific sources Chl-a. both relatively inaccurate for characterizing density. For different trophic states lakes, nutrient concentration changes affect phytoplankton. During seasons, fluorescence intensity response environmental conditions prevent results reflecting authentic Furthermore, high species diversity can lead inconsistent because content individual cells is different. relationship specific. Therefore, when applying it necessary consider conditions, community structure other practical conditions. addition, analytical instrumental techniques instruments need improved.

Language: Английский

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Endogenous phosphorus release from plateau lakes responds significantly to temperature variability over the last 50 years

Journal of Environmental Management, Journal Year: 2024, Volume and Issue: 371, P. 123259 - 123259

Published: Nov. 6, 2024

Language: Английский

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